How to Record a 12-Lead ECG: Step-by-Step Guide for Staff

A clean 12-lead ECG takes a few minutes when done properly. Use this guide to train nurses and technicians.

1. Prepare the patient

• Explain the procedure and ensure privacy.
• Lying supine, relaxed, arms at the sides.
• Remove metal objects near the electrode sites if needed.
• Keep the room warm to prevent shivering.

2. Prepare the skin

• Clean with an alcohol swab or soap and water and dry well.
• Shave hair at electrode sites if needed.
• Lightly abrade oily skin for better contact.

3. Place electrodes

• Limb electrodes: RA, LA, RL, LL on the wrists and ankles (or proximal limbs, consistently).
• Chest electrodes: V1–V6 at standard positions. See our detailed ECG electrode placement guide.

4. Machine settings

• Paper speed: 25 mm/s.
• Gain: 10 mm/mV.
• Filters: AC (50 Hz) and muscle filters as needed.
• Enter patient details (name, age, sex, ID).

5. Record

• Ask the patient to breathe normally and stay still.
• Check the screen for a stable baseline in all leads.
• Record and print or save.

6. Check quality

• All 12 leads present and labelled.
• No major artifacts. See ECG artifacts troubleshooting.
• Calibration pulse visible.
• Lead I mostly upright (if inverted, suspect limb lead reversal).

Common mistakes

• Chest electrodes placed too high.
• Limb lead reversal.
• A cold or talking patient.
• Dry or expired electrodes.

Equipment features that help

A colour touchscreen, lead-off detection and automatic measurements make good recordings easier. The Maestros 12 Channel ECG prints A4 reports in 3L, 6L or 12L formats.